1. Field of Invention
Embodiments of the present invention relate to a semiconductor device. More specifically, the embodiments of the present invention relate to a semiconductor memory device and a method of manufacturing the same.
2. Description of Related Art
A semiconductor memory device may include memory cells in which data may be stored. In general, the memory cells may be 2-dimensionally arranged within a limited area. In this case, to provide a high-capacity subminiature semiconductor memory device, the integration density of the memory cells may be increased by reducing the size of each of the memory cells.
The size of the memory cells may not be further reduced to a certain size to ensure reliability. Also, the size of the memory cells may not be further reduced due to the restrictions of a manufacturing process. As described above, there is a limit in reducing the size of the memory cells. To overcome the limitation while increasing the integration density of the memory cells within a limited area, a semiconductor memory device in which memory cells are 3-dimensionally arranged has been proposed.
A 3-dimensional semiconductor memory device may include word lines stacked on a substrate, apart from one another, a channel layer formed through the word lines ire a direction vertical to the substrate, a tunnel insulating layer formed to surround the channel layer, a charge storage layer formed to surround the tunnel insulating layer, and a blocking insulating layer formed to surround the charge storage layer. Memory cells may trap charges in a partial region of the charge storage layer disposed at intersections between the word lines and the channel layer to store data.
In the 3-dimensional semiconductor memory device, the charge storage layer may not be separated into respective memory cells but may be formed to surround the entire surfaces of sidewalls of the channel layer. Thus, charges stored in a specific memory cell may be transported to another memory cell along the charge storage layer. In this case, since it is difficult to ensure data retention characteristics, it may be difficult to ensure reliability of the 3-dimensional semiconductor memory device.